1. Field of the Invention
This invention relates to a reversible, unidirectional flow pump of the type generally referred to as a gerotor pump and more particularly, to a mechanism to effect positive rotation of a normally stationary eccentric ring in response to reversal of the pump rotor.
2. Description of the Prior Art
A reversible gerotor pump is sufficiently described in the above-referenced co-pending application and the prior art disclosed therein is pertinent to the problem of insuring proper orientation of a reversing eccentric in such a pump to maintain a common pump outlet regardless of the direction of rotation of the rotor. However, reference to FIG. 1 herein shows prior art apparatus more analogous to the present invention to positively effect such proper positioning of the eccentric ring. As will be subsequently explained, this prior art shows a spring biased plunger extending outwardly from its cavity in the rotor to frictionally engage the eccentric ring and establish frictional engagement between the ring and the plunger to cause rotation of the ring by the rotation of the rotor. However, once the ring is in proper position, continued rotation of the rotor causes the plunger to continue the frictional engagement of the ring which in turn causes undue wear and frictional drag resulting in premature failure of the apparatus and ultimately the pump.